My $.02: don't worry about it. Cut the edges as neatly as you can, be careful when rolling and squeegee-ing, but don't get retentive. The little threads will get sanded off when you feather it out before varnishing. I built a Tern, too, and given that the cloth overlaps at the center of the deck, this area turns out darker. Too bad Pygmy doesn't give the option of extra fiberglass cloth in the kit so you don't have to deal with the overlap of 2 different pieces. If the extra expense isn't a problem for you, you might think about getting a single piece about 18' long to do the deck all in one section. Maybe you have a West Marine nearby?

Dean